textproduct: Albany

WHAT HAS CHANGED

No significant changes with this update.

KEY MESSAGES

1) A widespread rainfall is expected late today through early Tuesday with the heaviest amounts likely across the mid-Hudson Valley into Litchfield County, CT. Isolated to scattered flash flooding will be possible, especially within urban and poor drainage areas.

2) Drier weather returns for the middle of the week with temperatures trending back above normal again later this week.

DISCUSSION

KEY MESSAGE 1...

A frontal boundary will be stalled just south of the region over the northern mid Atlantic States with waves of low pressure moving along this front through Tuesday. Rounds of showers and embedded thunderstorms are expected drift across the region by this evening and continuing into Tuesday Some areas will see repeated rounds of showers and thunderstorms, some of which can fall heavy at times, which will allow for a threat for excessive rainfall and flash flooding.

PWAT values are expected to increase to 1.50 to around 2.00 inches tonight and continue into early Tuesday. The values across southern areas are about 150%-180% of normal, which is about 2 STD above normal. Model soundings are showing plenty of signs for excessive rainfall, including a moist profile throughout the column, skinny CAPE profile, high PWATs and a high freezing level, indicating the potential for warm- rain processes and efficient rainfall production. Rainfall rates may easily exceed 1 inch per hour within thunderstorms with this setup. The 12z SPC HREF PMM 3hr totals shows pockets of 1-2 inches of rainfall within the high terrain of our southern areas, which are impressive amounts for an ensemble.

It remains uncertainty where the best corridor of heaviest rain sets up but the probabilities for this occurring are highest for areas south of Albany, especially across Ulster, Dutchess and Litchfield counties, where a Flood Watch for flash flooding remains in effect. WPC has also placed areas south of Albany in a slight risk for excessive rainfall (level 2 of 4) for Monday. There was not enough confidence in flooding concerns to expand the Flood Watch northward at this time but trends will be monitored. Within the slight risk area, flooding of urban and poor drainage areas are possible along with isolated to scattered instances of flash flooding. Total rainfall amounts of 1 to 3 inches remain possible south of Albany through Tuesday with localized amounts in excess of 3 inches possible, especially where repeated rounds of heavy rain occur.

KEY MESSAGE 2...

Nearly zonal flow returns to the region for the mid to late week period as high pressure builds in for Wednesday. This will bring a drier day to the area with near seasonable temperatures. Temperatures look to trend slightly above normal later this week with an uptick in humidity levels. An approaching low pressure system and cold front will bring increased chances for showers and thunderstorms for the end of the week as well.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

Through 18z/Monday...VFR conditions are expected to continue through the rest of the afternoon until around 23z/00z this evening. Broken and overcast mid and high level clouds start to lower after sunrise as a stationary front and slow moving low pressure system bring stratiform rain arriving first at KPOU at about 23z. Showers may start off remaining VFR but become steadier for the second half of the night, likely lowering to MVFR conditions especially at KPOU and KALB. The highest confidence for IFR is at KPOU with moderate to heavy rainfall lowering vis and cigs. Periods of LIFR cigs are also likely. KALB could also see periods of IFR/LIFR as low stratus extends more northward. KPSF and KGFL should remain outside of any of the heavier rain with just some lighter showers making it that far north, however KPSF and KGFL could still see MVFR conditions during these showers. Conditions at KPSF and KGFL will begin to improve first towards the end of the TAF period. There is also a chance of mist/fog developing in valley areas especially in areas that receive rain, the best chance of IFR conditions at KALB, KPOU, and KPSF. Showers remain at KPOU and possibly at KALB through the end of the TAF period. A few rumbles of thunder can't be ruled out this evening but it doesn't appear to be of high enough confidence to include in the TAFs. Winds out of the northeast/southeast 4-8 kt this afternoon become generally 5 kt or less and variable overnight. By morning winds pick back up with speeds 5-10 kt out of the southeast at KGFL, KALB, and KPSF and out of the northeast at KPOU.

Outlook...

Monday Night: High Operational Impact. Likely SHRA. Tuesday: High Operational Impact. Likely SHRA...TSRA. Tuesday Night: Low Operational Impact. Slight Chance of SHRA. Wednesday: No Operational Impact. NO SIG WX. Wednesday Night: No Operational Impact. NO SIG WX. Thursday: Low Operational Impact. Slight Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: High Operational Impact. Likely SHRA...TSRA.

ALY WATCHES/WARNINGS/ADVISORIES

CT...Flood Watch from late tonight through Tuesday morning for CTZ001-013. NY...Flood Watch from late tonight through Tuesday morning for NYZ063>066. MA...None. VT...None.